Most froth flotation equipment comprises a tank for pulp, an agitator in the form of a rotor and means for introducing and dispersing air into the agitated pulp.
One of the objectives associated with flotation equipment is the maximisation of the pulp particle/air contact. As the pulp particles continuously fall under gravity and the air bubbles continuously rise it is often difficult to improve interaction and contact times. For this reason air is often supplied to the equipment under pressure and forcibly introduced into the tank.
A rotor can be used to provide a pumping or lifting action to the pulp. Thus, instead of merely agitating the pulp the rotor imparts a definite upward movement to the pulp thereby increasing the overall suspension time of pulp particles in the upper reaches of the tank and consequently improving contact times.
It must be understood that the term "rotor" as used in this specification is intended to include within its scope impellers and agitators and the term "pulp stream" is intended to refer to pulp pumped by the rotor.
An object of this invention is to provide flotation equipment in which air/particle contact times are improved without the necessity of using compressed air.